Are nulls stored in a nonclustered index?

When you index a nullable field, are the rows with nulls stored in the index? It’s easy enough to find out by creating a table with a nullable field, and then creating an index on it.

Speedy Table Variables

Can deleting rows make a table…bigger?

Michael J. Swart posted an interesting question: he had a large table with 7.5 billion rows and 5 indexes. When he deleted 10 million rows, he noticed that the indexes were getting larger, not smaller.

Indexing Computed Columns

Unused Indexes - Are they really unused or have they just not been used YET?

Tara explains when index DMVs gets reset by telling a story from her dark past.

Index Tuning Week: How Many Indexes Are Too Many?

When you're not sure, start by aiming for 5 or less indexes per table, with 5 or less fields each.

sp_helpindex2

modernized sp_helpindex with info on post S2K features

Indexing the PO

Indexing a Computed Column

SQL Server Index Tutorial Overview

Although there are many different things that can be done to improve the performance of a database system, creating an index is the main tool in every DBA's toolbox that is used when we are trying to improve the performance of a query.